Ambidentate H-bonding of NO and O2 in heme proteins
نویسندگان
چکیده
منابع مشابه
Effective intermediate-spin iron in O2-transporting heme proteins.
Proteins carrying an iron-porphyrin (heme) cofactor are essential for biological O2 management. The nature of Fe-O2 bonding in hemoproteins is debated for decades. We used energy-sampling and rapid-scan X-ray Kβ emission and K-edge absorption spectroscopy as well as quantum chemistry to determine molecular and electronic structures of unligated (deoxy), CO-inhibited (carboxy), and O2-bound (oxy...
متن کاملBinding and Docking Interactions of NO, CO and O2 in Heme Proteins as Probed by Density Functional Theory
Dynamics and reactivity in heme proteins include direct and indirect interactions of the ligands/substrates like CO, NO and O(2) with the environment. Direct electrostatic interactions result from amino acid side chains in the inner cavities and/or metal coordination in the active site, whereas indirect interactions result by ligands in the same coordination sphere. Interactions play a crucial ...
متن کاملOzone model for bonding of an O2 to heme in oxyhemoglobin.
Several rather different models of the Fe-o2 bond in oxyhemoglobin have previously been proposed, none of which provide a satisfactory explanation of several properties. We propose a new model for the bonding of an O2 to the Fe of myoglobin and hemoglobin and report ab initio generalized valence bond and configuration interaction calculations on FeO2 that corroborate this model. Our model is ba...
متن کاملVectorial proton transfer coupled to reduction of O2 and NO by a heme-copper oxidase.
The heme-copper oxidase (HCuO) superfamily consists of integral membrane proteins that catalyze the reduction of either oxygen or nitric oxide. The HCuOs that reduce O(2) to H(2)O couple this reaction to the generation of a transmembrane proton gradient by using electrons and protons from opposite sides of the membrane and by pumping protons from inside the cell or organelle to the outside. The...
متن کاملHow O2 Binds to Heme
We have used density functional methods to calculate fully relaxed potential energy curves of the seven lowest electronic states during the binding of O2 to a realistic model of ferrous deoxyheme. Beyond a Fe–O distance of 2.5 Å, we find a broad crossing region with five electronic states within 15 kJ/mol. The almost parallel surfaces strongly facilitate spin inversion, which is necessary in th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Inorganic Biochemistry
سال: 2012
ISSN: 0162-0134
DOI: 10.1016/j.jinorgbio.2012.05.013